Kev almost had it, AKKING is accurate.
Here is an easy natural tip. Remember Kev said Ginger Ale....its the Ginger. A couple of days before drink some Ginger tea, coupla times a day. Anything Ginger will help. Try some ginger capsules a couple of hours in advance of hitting the water.

The stuff works...and NO side effects! also good for morning sickness too.

scopolamine patch behind the ear is the next best, it just turn it up a notch.
Paul